Three-dimensional printing device

Abstract

The disclosure provides a three-dimensional (3D) printing device including a tank, a forming stage and an irradiation unit. The tank is filled with a liquid forming material. The forming stage is movably disposed at the tank. The irradiation unit is disposed beside the tank and includes an image source and a projecting lens. The image source is used to emit an image beam. The image beam passes through the projecting lens to irradiate and cure the liquid forming material. An entrance pupil position of the projecting lens is ENP and 2000 mm≤ENP≤15000 mm. An exit pupil position of the projecting lens is EXP and 2000 mm≤|EXP|≤15000 mm.

What is claimed is: 
     
       1. A three-dimensional printing device comprising:
 a tank, filled with a liquid forming material; 
 a forming stage, movably disposed in the tank; and 
 an irradiation unit, disposed beside the tank and comprising:
 an image source for emitting an image beam; and 
 a projecting lens, through which the image beam passes to irradiate and cure the liquid forming material, wherein the projecting lens has an optical axis and comprises a plurality of lenses in sequence from an object side to an image side, each of the lenses having an object side surface facing the object side and an image side surface facing the image side, the projecting lens has an entrance pupil, an entrance pupil position of the projecting lens is ENP and refers to a distance from an intersection point of the image side surface of a first lens of the plurality of lenses of the projecting lens counted from the image side and the optical axis to an intersection point of a plane where the entrance pupil is located and the optical axis, and 2000 mm≤ENP≤15000 mm; and the projecting lens has an exit pupil, an exit pupil position of the projecting lens is EXP and refers to a distance from an intersection point of the object side surface of a first lens of the plurality of lenses of the projecting lens counted from the object side and the optical axis to an intersection point of a plane where the exit pupil is located and the optical axis, and 2000 mm≤|EXP|≤15000 mm. 
 
 
     
     
       2. The three-dimensional printing device according to  claim 1 , wherein an effective focal length of the projecting lens is EFL, and 320 mm≤EFL≤2270 mm. 
     
     
       3. The three-dimensional printing device according to  claim 1 , wherein the projecting lens has an f-number F/#, and 1.5≤F/#≤5.6. 
     
     
       4. The three-dimensional printing device according to  claim 1 , wherein the projecting lens has the optical axis and comprises the first lens of the plurality of lenses of the projecting lens counted from the object side, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens in sequence from the object side to the image side, the eighth lens is the first lens of the plurality of lenses of the projecting lens counted from the image side, and each of the first lens of the plurality of lenses of the projecting lens counted from the object side to the eighth lens has the object side surface facing the object side and allowing passage of the image beam therethrough and the image side surface facing the image side and allowing passage of the image beam therethrough. 
     
     
       5. The three-dimensional printing device according to  claim 4 , wherein the object side surface and the image side surface of the first lens of the plurality of lenses of the projecting lens counted from the object side are respectively a concave surface and a convex surface, and the object side surface and the image side surface of the second lens are both convex surfaces. 
     
     
       6. The three-dimensional printing device according to  claim 4 , wherein the object side surface and the image side surface of the third lens are respectively a convex surface and a concave surface, and the object side surface and the image side surface of the fourth lens are respectively a concave surface and a convex surface. 
     
     
       7. The three-dimensional printing device according to  claim 4 , wherein the object side surface and the image side surface of the fifth lens are respectively a concave surface and a convex surface, and the object side surface and the image side surface of the sixth lens are respectively a concave surface and a convex surface. 
     
     
       8. The three-dimensional printing device according to  claim 4 , wherein the object side surface and the image side surface of the seventh lens are respectively a convex surface and a concave surface, and the object side surface and the image side surface of the eighth lens are both convex surfaces. 
     
     
       9. The three-dimensional printing device according to  claim 1 , wherein a forming area closest to the forming stage in the projecting lens is A 1 , the forming stage has a carrying surface facing the projecting lens, an area of the carrying surface is A 2 , and 0.14≤A 1 /A 2 ≤1.